mtd: rawnand: Check the data only read pattern only once

Instead of checking if a pattern is supported each time we need it,
let's create a bitfield that only the core would be allowed to fill at
startup time. The core and the individual drivers may then use it in
order to check what operation they should use. This bitfield is supposed
to grow over time.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Liao Jaime <jaimeliao.tw@gmail.com>
Link: https://lore.kernel.org/linux-mtd/20230112093637.987838-2-miquel.raynal@bootlin.com

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index c3cc660399255469c7f427fffc6780e8b1a6c83e..7b87e2e7048452915a3ebb00cc190e912bc8f73a 100644 (file)
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -4991,6 +4991,24 @@ nand_manufacturer_name(const struct nand_manufacturer_desc *manufacturer_desc)
        return manufacturer_desc ? manufacturer_desc->name : "Unknown";
 }
 
+static void rawnand_check_data_only_read_support(struct nand_chip *chip)
+{
+       /* Use an arbitrary size for the check */
+       if (!nand_read_data_op(chip, NULL, SZ_512, true, true))
+               chip->controller->supported_op.data_only_read = 1;
+}
+
+static void rawnand_early_check_supported_ops(struct nand_chip *chip)
+{
+       /* The supported_op fields should not be set by individual drivers */
+       WARN_ON_ONCE(chip->controller->supported_op.data_only_read);
+
+       if (!nand_has_exec_op(chip))
+               return;
+
+       rawnand_check_data_only_read_support(chip);
+}
+
 /*
  * Get the flash and manufacturer id and lookup if the type is supported.
  */
@@ -5023,6 +5041,8 @@ static int nand_detect(struct nand_chip *chip, struct nand_flash_dev *type)
        /* Select the device */
        nand_select_target(chip, 0);
 
+       rawnand_early_check_supported_ops(chip);
+
        /* Send the command for reading device ID */
        ret = nand_readid_op(chip, 0, id_data, 2);
        if (ret)

diff --git a/drivers/mtd/nand/raw/nand_jedec.c b/drivers/mtd/nand/raw/nand_jedec.c
index 85b6d9372d80b992fe3904715cb7f7363c2781df..836757717660b92612253c1e4244c80cbe35ba57 100644 (file)
--- a/drivers/mtd/nand/raw/nand_jedec.c
+++ b/drivers/mtd/nand/raw/nand_jedec.c
@@ -46,8 +46,7 @@ int nand_jedec_detect(struct nand_chip *chip)
        if (!p)
                return -ENOMEM;
 
-       if (!nand_has_exec_op(chip) ||
-           !nand_read_data_op(chip, p, sizeof(*p), true, true))
+       if (!nand_has_exec_op(chip) || chip->controller->supported_op.data_only_read)
                use_datain = true;
 
        for (i = 0; i < JEDEC_PARAM_PAGES; i++) {

diff --git a/drivers/mtd/nand/raw/nand_onfi.c b/drivers/mtd/nand/raw/nand_onfi.c
index 7586befce7f920defe3dcceefb2d8ee08172f281..f15ef90aec8cd6d76f3c4da5d078d1c5ddfd1fdc 100644 (file)
--- a/drivers/mtd/nand/raw/nand_onfi.c
+++ b/drivers/mtd/nand/raw/nand_onfi.c
@@ -166,8 +166,7 @@ int nand_onfi_detect(struct nand_chip *chip)
        if (!pbuf)
                return -ENOMEM;
 
-       if (!nand_has_exec_op(chip) ||
-           !nand_read_data_op(chip, &pbuf[0], sizeof(*pbuf), true, true))
+       if (!nand_has_exec_op(chip) || chip->controller->supported_op.data_only_read)
                use_datain = true;
 
        for (i = 0; i < ONFI_PARAM_PAGES; i++) {

diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
index dcf90144d70b7588edf36629967d6a21df3d5282..28c5dce782ddc61f51444668c7ef3cc385d2f9bc 100644 (file)
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -1094,10 +1094,18 @@ struct nand_controller_ops {
  *
  * @lock:              lock used to serialize accesses to the NAND controller
  * @ops:               NAND controller operations.
+ * @supported_op:      NAND controller known-to-be-supported operations,
+ *                     only writable by the core after initial checking.
+ * @supported_op.data_only_read: The controller supports reading more data from
+ *                     the bus without restarting an entire read operation nor
+ *                     changing the column.
  */
 struct nand_controller {
        struct mutex lock;
        const struct nand_controller_ops *ops;
+       struct {
+               unsigned int data_only_read: 1;
+       } supported_op;
 };
 
 static inline void nand_controller_init(struct nand_controller *nfc)